Conventionally, as disclosed in the following Patent Literature 1, for example, an exhaust heat recovery device including a binary electricity generation device is known. In an exhaust heat recovery device disclosed in the following Patent Literature 1, it is designed such that a working medium is evaporated in an evaporator of a binary electricity generation device, using heat of cooling water of an engine, and a power turbine is driven by the evaporated working medium, to generate electricity.
In the above-described exhaust heat recovery device disclosed in Patent Literature 1, cooling water of an engine is used as a heat source for evaporating a working medium of the binary electricity generation device. In the meantime, it is conceivable to use heat of an exhaust gas as a heat source. In this case, in an attempt to recover heat from an exhaust gas containing a corrosive component such as sulfur, there is a fear that a corrosive component may condense from a low-temperature exhaust gas from which heat is recovered, to corrode a pipe and the like. For this reason, it is unable to excessively recover heat of an exhaust gas, and thus, there arises a problem of inability to efficiently generate electricity.